1. Field of the Invention
The present invention relates to an apparatus for guiding a tape in a video cassette tape recorder, and in particular to an improved apparatus for guiding a tape in a video cassette tape recorder capable of advantageously protecting a tape from being caught at a guide pole of a take-up arm when a cassette is ejected from a video cassette tape recorder.
2. Description of the Conventional Art
Conventionally, as shown in FIG. 1, in a video cassette tape recorder a tape 3 is fed through a take-up arm 4, a pinch roller 2, a capstan motor shaft 1, a first tape running guide 5, an audio control head 6, a take-up impedance roller 7, a dram 8, a supply loading post 9, a supply impedance roller 10, a erasing head 11, a second tape running guide 12, and a pair of third tape running guides 13.
In addition, FIG. 2A shows a position of a guide pole 29 when a cassette is not fed into the video cassette tape recorder body that is, any operation mode is not applied thereto. FIG. 2B shows a position of the guide pole 29 when the cassette is fed into the video cassette tape recorder body and then a tape thereof is being guided toward a pinch roller 15. FIG. 3 shows a position of the guide pole 29 when a tape loading operation is finished, so the tape 3 is position at the back of the pinch roller 15.
The construction of the conventional apparatus for guiding a tape in a video cassette tape recorder will now be explained with reference to FIGS. 2A to 2B through 3.
To begin with, a pinch roller assembly 50 includes a pinch gear 20 mounted on a predetermined portion of a stationary base plate 150 for receiving a predetermined rotation force from a motor (not shown) and transferring the rotation force to corresponding elements connected thereto. A pinch gear shaft 20' is fitted into the pinch gear 20. A semicircular cam 23 is formed on the pinch gear 20 in a form of surrounding the pinch gear shaft 20'. A cam groove 21 is formed on the outer circumferential surface of the pinch gear shaft 20'. An arm pinch 22 is rotatably mounted on the top of the pinch gear shaft 20'. A pinch lever 25 is mounted on the top of the pinch gear shaft 20'. One end of the pinch lever 25 is connected to one end of a pinch plate 16. A pinch roller 15 is mounted on the other end of the pinch plate 16. Here, a spring 24 is connected between the top of the pinch gear shaft 20' and a predetermined portion of the pinch plate 16.
Meanwhile, a take-up lever 26 is mounted on a predetermined portion of the stationary base plate 150. A pinch roller taking up/down shaft 18 is fitted to the central portion of the take-up lever 26, the top of which is connected to a predetermined portion of the pinch plate 16. Here, one end of the pinch roller taking up/down shaft 18 comes into slidable contact with the outer circumferential surface of the semicircular cam 23 and the other end thereof is intermeshed with the gear 27 integrally formed with a take-up arm 28 including a guide pole 29. Here, a guide pole head 29a is formed on the top of the guide pole 29 to prevent a tape 3 from drifting away from the guide pole 29 when the tape is running.
The operation of the conventional apparatus for guiding a tape in a video cassette tape recorder will now be explained with reference to FIGS. 1, 2A to 2B and 3.
To begin with, before a cassette is loaded into a video cassette tape recorder body, the take-up arm 28 stays near the pinch roller 15. At this state, when the cassette is loaded thereinto in accordance with a predetermined operation mode, the take-up arm 28 moves toward a take-up reel (not shown) and a supply reel (not shown) so as to guide the tape 3 toward the back of the pinch roller 15 by receiving a predetermined rotation force from the motor via the pinch gear 20 and the take-up lever 26. Here, the pinch roller 15 is directed to be raised up/down by a predetermined operation of the pinch gear and the cam groove 21. By the continued operation of the pinch gear 20 and the take-up lever 26, the tape 3 is engaged to the back of the pinch roller 15.
Meanwhile, when the tape 3 is ejected from the guide pole 29 and the guide pole head 29a, the take-up arm 28 rotates counterclockwise by a predetermined rotation force applied from the pinch gear 20, the cam 23, the take-up lever 26 and the gear 27. When the take-up arm 28 finishes rotating counterclockwise, the cassette is raised up so as to be unloaded from the take-up reel and the supply reel and at the same time the take-up arm 28 goes back toward the pinch roller 15.
However, when the take-up arm 28 goes back toward the pinch roller 15 after the cassette is raised up so as to be unloaded from the take-up reel and the supply reel, the tape 3 is caught at the guide pole head 29a and/or the top of the guide pole 29 because generally the guide pole head 29a has a larger diameter than that of the guide pole 29 in order to prevent the tape 3 from drifting away from the guide pole 29 when the tape 3 is running. In addition, due to the different timing between when the cassette is raised up from the take-up reel and the supply reel and when the take-up lever 26 goes back toward the pinch roller and the manufacturing variations in the corresponding parts, the tape 3 is from time to time caught at the guide pole 29 and/or the guide pole head 29a, whereby the tape 3 may be damaged or the video cassette tape recorder malfunction.